Needle assembly of probe card

ABSTRACT

A needle assembly of probe card includes a needle guide plate and needle plates formed therein for enhancing an assembly characteristic and a productivity and increasing an exact and reliable characteristic test. The needle guide plate is provided with needle movable holes that are formed with an insulating film on a circumferential surface thereof. One side end surface of the needle plate adheres on an inner side surface of the needle movable hole, another side end surface thereof is spaced from a circumferential surface of the needle movable hole, and a vertical thickness of the other side of the needle movable hole is formed thinner than the needle guide plate so as to have a space in which the other side can vertically move upward and downward. The needle guide plate and the needle plate are combined into one body.

PRIORITY

[0001] This application claims priority to an application entitled “Needle Assembly of Probe Card” filed in the Korean Industrial Property Office on Apr. 11, 2003 and assigned Serial No. 2003-22937, the contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a characteristic test for semiconductor devices, and more particularly, to a needle assembly of probe card for performing a stabilized characteristic test for miniaturized and high-integrated semiconductor devices.

DESCRIPTION OF THE RELATED ART

[0003] Semiconductor devices are generally manufactured through fabrication processes of forming patterns on wafers and assembly processes of assembling the pattern-formed wafers into respective chips.

[0004] Between the fabrication processes and the assembly processes, an electrical die sorting (hereinafter, referred to as ‘EDS’) process is generally performed to test electrical characteristics of the respective chips formed on a wafer.

[0005] The EDS process is applied particularly to separate defective chips from the normal chips formed on the wafer, and employs a test apparatus of detecting the defective chips by simply applying electric signals to the chips constituting the wafer and using the resultant electric signals. That is, in order to perform the electric test for the chips constituting the wafer, it is used a test apparatus called a probe card that is provided therein with a plurality of needles which are in contact with the patterns of each chip and through which the electric signals are applied to the chip.

[0006] If the semiconductor device was tested as a good quality by the probe card, the semiconductor device is transferred for post processes such as a packaging process etc., so that the semiconductor devices may be manufactured as final products by a packing process.

[0007] During the electrical characteristic test of the semiconductor device, a needle of probe card is in contact with an electrode pad of each semiconductor device that is generally formed on a wafer, and a specific current from a specific tester flows through the needle so as to measure and detect the electrical characteristic.

[0008] In the meantime, the semiconductor devices are recently on a continuously development tendency for a high integration and an extremely miniaturized size. Therefore, its appropriately corresponding test apparatuses have been required for test of the semiconductor devices on this tendency and accordingly made, and there have been many tries to properly perform the test of high-integration semiconductor devices with probe cards of the apparatuses thus made.

[0009] As a result, such conventional test apparatuses of the semiconductor devices make interval between needles become narrowed, and simultaneously shorten the transmission path of electric signals, the needles being contacted with an electrode pad of the semiconductor device from a main substrate.

[0010] However, to realize the test apparatus for testing the high-integration semiconductor devices, a thickness of needle itself must be as minimized as possible and intervals between these needles having such a minimized thickness must be fined too.

[0011] In order to finely form the thickness of needles and the intervals between the needles, components for supporting these needles should be formed with a fine pattern, and it is further required a configuration that is capable of stably transferring electric signals from the main substrate to these finely formed needles. Very complicated and delicate process technique is therefore needed to realize this configuration.

SUMMARY OF THE INVENTION

[0012] One feature of the present invention provides a needle assembly of a probe card that is appropriately employed for test of high integrated and miniaturized semiconductor devices according to a current technical tendency, by more finely forming thickness of needles and intervals between the needles.

[0013] Another feature of the present invention is to provide a probe card to reduce the number of assembling processes and increase productivity by unifying needles being contacted with electrode pads of a semiconductor device and components supporting the needles into a needle assembly.

[0014] To approach these features, according to one aspect of the present invention, a needle assembly of probe card includes a needle guide plate and needle plate formed therein. The needle guide plate as a thin plate made of silicon material is formed therein in a predetermined interval with needle-movable holes having predetermined width and length, and is formed with an insulating film of a predetermined thickness at an inner circumferential surface of each of the needle movable holes. One side of the needle plate may adhere to one side of the needle movable hole in a length width direction, and another side end surface thereof is spaced in a predetermined gap from a circumferential surface of the needle movable hole, and a vertical thickness of another side excepting one-side end part adhering to the one side surface of the needle movable hole is formed thinner than the needle guide plate, so as to have a space in which the another side can vertically move upward and downward.

[0015] According to another aspect of the present invention, a needle assembly of probe card includes a needle guide plate, a needle plate and a circuit substrate. The needle guide plate as a thin plate made of silicon material is provided with a needle movable hole that has predetermined width and length by a predetermined interval, the needle movable holes being provided with an insulating film that is formed with a predetermined thickness on a circumferential face thereof. Further, in the needle plate, one side end surface thereof adheres on one side face of a length direction of the needle movable hole, and another-side end surface thereof have a predetermined gap from a circumferential surface of the needle movable hole, and a vertical thickness of another side excepting one-side end part adhering to the one side face of the needle movable hole is formed thinner than the needle guide plate, so as to have a movement space in which the another side can vertically move upward and downward. Also, the circuit substrate is formed with a determined thickness on an upper part of the needle guide plate, and a plate face thereof has a vertical contact hole so as to be electrically connected to an upper part of the needle plate. Further, on the circuit substrate, a circuit is formed to electrically connect the contact hole with a connection pattern formed on an upper face of the circuit substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The foregoing and other features and advantages of the invention will be apparent from the more particular description of exemplary embodiments of the invention, as illustrated in the accompanying drawings, in which:

[0017]FIG. 1 is a sectional view of a needle assembly according to one exemplary embodiment of the present invention;

[0018]FIG. 2 is a bottom view of FIG. 1;

[0019]FIG. 3 is a cross sectional view of a needle assembly according to another exemplary embodiment of the present invention; and

[0020]FIG. 4 is an operational state view of a needle plate according to the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0021] The present invention and exemplary embodiments thereof are more fully described below with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein; rather, these exemplary embodiments are provided so that this disclosure is thorough and complete, and conveys the concept of the invention to those skilled in the art.

[0022]FIG. 1 is a side sectional view illustrating a needle of a probe card for use in a characteristic test of a semiconductor device according to one exemplary embodiment of the present invention.

[0023] A needle assembly of the invention has inventive characteristics that a needle guide plate 10 and a needle plate 20 are integrated into one body.

[0024] It is desirable that the needle guide plate 10 be made of silicon material and the needle plate 20 be made of conductive material that is proper to a unified formation with the needle guide plate 10.

[0025] Describing more in detail, the needle guide plate 10 is made of a thin plate of silicon material having a predetermined thickness, and is provided therethrough with needle movable holes 11 having predetermined width and length at a predetermined interval.

[0026] The needle guide plate 10 is formed with an insulating film 12 having a predetermined thickness on an inner circumferential surface of the needle movable hole 11 and in an upper portion and a lower portion of the plate face.

[0027] It is desirable that this insulating film 12 is formed of oxide film and silicon nitride film SiN.

[0028] The needle plate 20 is made of conductive material in the present invention. The conductive material should be proper to a chemical vapor deposition. For example, nickel or beryllium copper and even other various materials may be used.

[0029] Describing in more detail the needle plate 20, one side thereof adheres to one side surface of the needle movable hole 11 that is formed in a vertical direction in the needle guide plate 10, and another side surfaces thereof are a little spaced from an inner circumferential surface of the needle movable hole 11 to form a movable gap 13 as shown in FIG. 2. In particular, the needle plate 20 is formed in a “L” shape and one side of the “L” shape of the needle plate 20 is fixed to one side of the inner surface of the movable hole 11, so that the other end side of the needle plate 20 may be movable upward and downward with an axis fixed to the needle guide plate 10.

[0030] Further, a needle tip 21 having a given size is formed by being projected downward from a lower surface of the needle plate 20 opposite to one side of the needle plate 20 adhering to the needle guide plate 10. Since the needle tip 21 is in contact with a connection pad of a semiconductor device, it is desirable that a lower end part of the needle tip 21 is sharp-pointed to thereby be in point contact with the connection pad of the semiconductor device, rather than in surface contact with the connection pad, to reduce a contact resistance through the point contact.

[0031] The variable gap 13 between the insulating film 12 and the another end side opposite the one side of the needle plate 20 which moves upward should be formed to have an enough space, so that any contact between the insulating film 12 and the another end side may be prevented when the one side of the needle plate 20, i.e, the side where the needle tip 21 is positioned, moves upward and downward (may fluctuate upward and downward).

[0032] Meanwhile, as shown in FIG. 3, a circuit substrate 30 may be integrated into the needle assembly of the present invention.

[0033] That is, the circuit substrate 30 may be integrated into the needle assembly as one body to be deposited on or adhere to an upper surface of the needle guide plate 10, so that an electrical signal is effectively transmitted from a main substrate of the probe card to the needle plate 20. The circuit substrate 30 is provided with connection pads 31 that are formed on an upper surface thereof and that are electrically connected to an electrical signal connection unit equipped on an upper side of the connection pad 31.

[0034] In addition, as shown in FIG. 3, the circuit substrate 30 is formed therein with contacts 32 that are made by being filled with a conductive material. The contact 32 is in contact with the needle plate 20 at the upper surface of the needle plate 20 that is in contact with the circuit substrate 30. The upper portion of the contact 32 is connected with a pattern formed on the circuit substrate 30 so as to be electrically communicated with the connection pads 31.

[0035] Such a needle assembly of the present invention may be fabricated using a conventional semiconductor device fabricating method. That is, the needle assembly of the present invention may be fabricated by using several processes such as photolithography process, etching process, a deposition process such as a chemical vapor deposition (CVD), and a polishing process, which have been already used in fabricating semiconductor devices. For example, the needle guide plate 10 of a silicon plane plate having a given thickness is etched to form needle movable holes 11 using a photolithography process and the needle plate 20 is formed in the needle movable holes 11 by using the deposition process, particularly a low pressure chemical vapor deposition (LPCVD) process. Of course, additional many processes may be used in fabricating the needle assembly of the present invention.

[0036] The insulating film 12, which is formed of a portion being in contact with and a portion being not in contact with the L shaped needle plate 20, is formed by depositing silicon nitride that is different from the needle plate 20 of oxide film on an inner circumference surface of the needle movable hole 11 of the needle guide plate 10.

[0037] A needle tip 21 to be contacted with an electrode pad of a semiconductor device is formed, being projected to a predetermined height, at a lower surface of one end part of the needle plate 20, which may move upward and downward. The needle tip 21 may be formed on the needle plate 20 through a separate deposition process.

[0038] The circuit substrate 30 may be deposited or mounted on an upper surface of the needle guide plate 10 which is formed with the needle plate 20 in one body.

[0039] The circuit substrate 30 may be formed thereon with circuit patterns by using a photolithography process and a deposition process like on the needle guide plate 10.

[0040] It is desirable that an upper surface and a lower surface of the needle guide plate 10 are planarized using a planarization process such as a polishing process.

[0041] The operation of the present invention thus constructed will be described as follows.

[0042] The present invention has a feature that needle being contacted with an electrode pad of a semiconductor device is integrated into the needle assembly in one body, thereby allowing the distance between the needles to be formed more densely.

[0043] In particular, there is an advantage that the needle plate 20 provided in the needle guide plate 10 may be configured to move upward and downward at one end portion thereof by a predetermined angle, as shown in FIG. 4, thus the needle plate 20 operates as a buffer against an impact that may be caused by a direct contact with an electrode pad of a semiconductor device. Further, in the configuration of the needle assembly, the needle plate 20 and the circuit substrate 30 are formed in one body with the needle guide plate 10, to thus provide a convenience in performing an assembly process for later manufacturing a probe card.

[0044] That is, a conventional needle assembly is fabricated by forming separately and assembling respectively needles, needle guide plates supporting the needles, and circuit substrates for transferring an electrical signal to the needles. However, in the present invention, the needle assembly is fabricated by unifying these components in a single body, thereby allowing the needle assembly to be assembled more easily with a probe card.

[0045] Accordingly, since the needle assemble of the present invention is fabricated by using the accurate and fine processes that are employed in forming patterns of semiconductor devices, the distance between the needle plates 20 may be fined, thereby providing a probe card capable of efficiently corresponding to patterns of semiconductor devices that tend to be miniaturized and high-integrated gradually.

[0046] As was described above, an assembly of needles contacted with an electrode pad of a semiconductor device is configured in one body and manufactured by using pattern forming processes of semiconductor devices, thereby enhancing an assembly characteristic and a productivity in manufacturing the probe card, and extremely miniaturizing the needles and substantially reducing the distance between the needles. Therefore, according to the present invention, even a high-integration semiconductor device can undergo an exact characteristic test.

[0047] The present invention increases reliability in test for semiconductor devices, in particular, even for corresponding to extremely miniaturized semiconductor devices.

[0048] It will be apparent to those skilled in the art that modifications and variations can be made in the present invention without deviating from the spirit or scope of the invention. Thus, it is intended that the present invention cover any such modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Accordingly, these and other changes and modifications are seen to be within the true spirit and scope of the invention as defined by the appended claims. 

What is claimed is:
 1. A needle assembly of a probe card, comprising: a needle guide plate as a thin plate made of silicon material, said needle guide plate being formed therein with needle movable holes having predetermined width and length and spaced from one another in a predetermined interval, said needle movable holes each being formed with an insulating film having a predetermined thickness on a circumferential surface thereof; and needle plates, a surface of one side portion of each of the needle plates being adhered on one side surface of each of the needle holes, a surface of another side portion of each of the needle plates being spaced from a circumferential surface of each of the needle holes with a predetermined needle movable gap, the other portion of each of the needle plates being formed thinner than the needle guide plate in a vertical direction so as to be movable upward and downward within the needle movable hole, wherein said needle guide plate and said needle plates are combined into one body.
 2. The assembly as claimed in 1, wherein the needle plate is “L”-shaped, a vertical portion of the “L”-shaped needle plate adhering to one side inner circumference surface of the needle movable hole of the needle guide plate, a horizontal portion of the “L” shaped needle plate being configured to be movable upward and downward.
 3. The assembly as claimed in 1, wherein the needle plate is provided with a needle tip that is projected downward a lower surface of the other side portion of the needle plate that is movable upward and downward.
 4. The assembly as claimed in 1, wherein the needle movable gap between the another side portion of the needle plate and the insulating film formed on an inner circumferential surface of the needle guide plate, has a width enough to prevent a contact between the insulating film and the another side portion of the needle plate when the other side portion of the needle plate moves upward and downward.
 5. A needle assembly of a probe card, comprising: a needle guide plate as a thin plate made of silicon material, said needle guide plate being formed therein with needle movable holes having predetermined width and length and spaced from one another in a predetermined interval, said needle movable holes each being formed with an insulating film having a predetermined thickness on a circumferential surface thereof; needle plates, a surface of one side portion of each of the needle plates being adhered on one side surface of each of the needle holes, a surface of another side portion of each of the needle plates being spaced from a circumferential surface of each of the needle holes with a predetermined needle movable gap, the other portion of each of the needle plates being formed thinner in thickness than the needle guide plate in a vertical direction so as to be movable upward and downward within the needle movable hole; and a circuit substrate formed on the needle guide plate with a predetermined thickness, the circuit substrate formed therein with contact holes by which the circuit substrate is electrically connected to the needle plate, the circuit substrate formed thereon with connection patterns electrically connected to the contact holes, wherein said needle guide plate, said needle plate, and said circuit substrate are combined into one body. 